Certain aircraft, such as commercial airplanes, often include environmental control systems, such as air conditioners and heaters, in order to keep the cabin temperature in a range comfortable for the occupants of the airplane. Although existing systems are effective in achieving cabin temperatures within an acceptable comfort range, temperature gradients within the cabin often exist, particularly for larger cabins, and occupants may experience “hot” or “cold” spots in some areas of the cabin.
In particular, some larger aircraft often have cold spots in the area around the doors or galleys of the airplane where factors such as heat loss due to airplane structure, insufficient insulation in and around the doors, and insufficient heat addition may contribute to the creation of a cold spot. Other factors may also contribute to the creation of temperature gradients in the cabin of an aircraft.
Such a cold spot can be particularly uncomfortable for persons that spend any appreciable time in the doorway or galley areas. For example, flight attendants or crew on a commercial aircraft are often seated in a jump seat in the doorway or galley area, and situations such as long duration night time flying with low activity in the cabin or turbulence may cause the crew to remain seated for extended periods.
Prior solutions to alleviate cold areas have included adding one or more of an electrical door air heater to flow warm air across the base of exit door bustles, electrically heated floor panels, heated sidewall panels, and heated door liner surface panels to address the temperature loss in door and galley areas. One drawback of these existing solutions is that because they heat the air, or the surfaces near the floor or door, they are less effective in providing direct thermal comfort to the persons located in the cold area.
Furthermore, these surface and air heaters are typically designed to be constantly powered on in order to sufficiently heat the cold space. Therefore, without proper operational control, adding these supplemental heating systems in areas such as doorways and galleys where occupancy is often transitory and temporary can be expensive and inefficient. Other drawbacks of existing solutions also exist.